#wrap {
	width: 800px;
	height: 400px;
	display: flex;
	flex-flow: row wrap;
	align-content: flex-start;
	border: 1px solid dimgray;
	box-sizing: border-box;
	.box {
		width: 25%;
		height: 50px;
		border-right: 1px solid dimgray;
		border-bottom: 1px solid dimgray;
	}
}